The Temporal Association of Robotic Surgical Diffusion with Overtreatment of the Small Renal Mass

Purpose: We evaluated contemporary practice patterns in the management of small renal masses. Materials and Methods: We identified 52,804 patients in the NCDB (National Cancer Database) who were diagnosed with a small renal mass (4 cm or less) between 2010 and 2014. Utilization trends of active surveillance, ablation and robotic, laparoscopic and open surgical techniques were compared among all comers, elderly patients 75 years old or older and individuals with competing health risks, defined as a Charlson index of 2 or greater. Multivariable logistic regression models were used to assess factors associated with robotic renal surgery and active surveillance. Results: Surgery remained the primary treatment modality across all years studied, performed in 75.0% and 74.2% of cases in 2010 and 2014, respectively. Although increases in active surveillance from 4.8% in 2010 to 6.0% in 2014 (p <0.001) and robotic renal surgery (22.1% in 2010 to 39.7% in 2014, p <0.001) were observed, the increase in the proportion of small renal masses treated with robotic partial and radical nephrectomy was greater than that of active surveillance (82.0% and 63.0%, respectively, vs 25.0%). Subgroup analyses in individuals 75 years old or older, or with a Charlson index of 2 or greater likewise revealed preferential increases in robotic surgery vs active surveillance. On multivariable analysis later year of diagnosis was associated with increased performance of robotic renal surgery compared to active surveillance (2014 vs 2010 OR 1.44, 95% CI 1.20-1.72, p <0.001) and non-robotic procedural interventions (2014 vs 2010 OR 2.59, 95% CI 2.30-2.93, p <0.001). Conclusions: Robotic surgical extirpation has outpaced the adoption of active surveillance of small renal masses. This raises concern that the diffusion of robotic technology propagates overtreatment, particularly among elderly and comorbid individuals.